Alternating-current motor.



f f UNITED J STATES PATENT OFFICE;

CARL EIOKEMEYER, MARY T. EICKEMEYER, AND RUDOLF EIOKEMEYER, JR., OFYONKERS, NEW YORK, EXEGUTORS OF RUDOLF EIOKEMEYER, DECEASED, ASSIGNORSTO THE GENERAL ELECTRIC COMPANY, or SGHEN- EOTADY, NEw YORK. A

ALTE RNATlNG-CURRENT MOTOR.

SBECIFIGATION formingpart of Letters Patent 0. 677,308, dated June 25,1901.

Original application filed July 6, 1894, $erial No. 516,724. Divided andthis application filed January 24, 1901. Serial No. 44,576. (No model.)

ToaZZ whom iii-may concern/.3 the object being'by these'several featuresof 50 Be it known thatRUDOLFEICKEMEYER,deconstruction to reduce themagnetic resist ceased, late of Yonkers, in the county of Westance ofthe armature to the lowestpracticable chesterand State of New York,during his degree; and foraffording specially ample maglifetime inventedcertain new and useful Irnnetio circuits and numerous closed circuitsprovements in Alternating-Current Motors, in the armature-core I arrangethe plugs in 55 and that we, CARL EIOKEMEYER, MAR Y T. concentric rowsor sets, s'othat' the plugs in EICKEMEYER, and RUDOLF EICKEMEYER, J r.,some of the rows will occupy different radial executors under the lastwill and testament linesfrom'those occupied by'the' other plugs.

of the said RUDOLF EICKEMEYER, do hereby Referring to'the drawings,Figures I and 2 declare to the best of our knowledge and beillustrate intwo diametrically opposite sec- 60 lief that the followingspecification, taken in tions an alternating-current machine embodyconnection with the drawings furnished and ing certain portions of theinvention. Figs, forming a part of the same, is a clear, true, 3 and 4,in en'd view and longitudinal sec and. complete description of saidimprovetions, illustrate a closed-circuit armature as mentsr i devisedand used in oneof its simplest forms. 65

This application is adivision of application Figs. 5 and 6, in twosections, illustrate an Serial No. 516,724, filed July 6,1894. armatureembodying an, iron core, copper The improvements hereinafter set forthreheads,'and inserted copper bars in accordlate to motors adapted forusein electric cirance with oneportion of the invention. Figs.

cuits wherein the current'alternates. 7 and 8, in two sections,illustrate still an 70 The armatures of the motors embody iron other ofthe armatures, having an iron core,

cores with tightly-inserted longitudinal copcopper head, and three rowsof. inserted copper conductors and j copper heads and are per plugs.Figs. 9, 10, 11, and 12 illustrate a novel in that said parts'are soorganized and motor havingla closed-circuit armature like united bysoldering as to constitute a subthat in'Fig. 1 and a field of suitableform 75 stantially integral solid structure and afiord provided withclosed-circuit starting-coils in the desired number of closed circuits,which the form of solid conductors, in part occupyare traversed bycurrentsinduced by the roing recesses in the cores of the field.

3o tation of the armature through and by the The machine A (shown inFigs. 1 and 2) has alternations of the magnetic field. In armaa fieldmagnet'or inducing member A, which 80 tures of this type thelongitudinal conductors contains sixteen field-coils a on a ring or coreare angularly arranged and in one or more composed of soft-iron plates1), the latter be concentric rows so disposed in theiron core inglater'allybored to receive the inner ends as to separate parts of itinto sections divided of the coils, which are otherwisemaintainedsubstantially on radial lines extending from in position bywedge-shaped blocks 0, inter- 85 the periphery inwardly, also in havingthe posed between the coils at their sides and field-poles and thelongitudinal conductors outer ends, the blocks and core-plates beingunsymmetrical with relation to each other, clamped together by means ofpins or bolts d.

so that no two magnet-poles can ever have a The bored holesin the coreare slitted through magnetic circuit (through portions of the to thearmature-space, as at b, for afiording' 9o core) which is precisely thesame as that of air-space between the pole-divisions or pole= any othertwo poles, and also in having the faces of the field-magnets, of whichthere are plugs (or longitudinal conductors) and poles sixteenintervening between the sixteen coils.

located unsymmetrically, so that no two ad- In. this machine, asoperated in accordance jacent plugs will occupy the same position withthe invention',the main circuit or supply 5 with relation to theiradjacent pole or poles connections are made with the set of fieldas anyother two similar plugs will occupy coils at two opposite points,(indicated at c with relation to their adjacent pole or poles, and f,)and the armatureB when once started is effectively driven by thisbipolarfield with out any variations in the 'applicatio'n'of the main currentor in the-field-coils, although for starting the motor a system ofshort-circuiting thev field-coils or rotation of thejfieldcoil terminalsis employed. Since such means for starting do not constitute a basis forclaims T in this case, no detailed description of the sameis deemednecessary;

The armature or induced member B contains certain novel features in itsconstruc-' tion by which highly-effective closed elec-' tric circuitsare aftordedj fand when considered [with reference to its-combinationwith the field described valuable novelty is involved in the fact thatthe numberof closed circuits i'n'the armature is a number which has nonumerical relationto the number of fieldpoles or polefaces, .or, inother words, the six-- teen field-coils and; pole-faces are here usediii-combination With an armature provided I with, seventeen conductors.For causingthe armature-poles to revolve with uniformity as to speedandstrength the armature-conductors should be numerous, and for securingthe best/results thev magnetic resistanceot the armature shouldbeuniform or equal in all directions'that is, the armature must not haveany well-defined pole-faces'corresponding in number to those of thefield. It is to beunderstood that this portion of the'invention extendsto any given number of pole-faces v in the, field and any given numberof conductors at the periphery of the armature, so long as said numberof conductors is indivisible by the 'number of field-poles orfhas nolarger common divisor therewith.

- The armature'B includesa corelg, of sott-' iron disks, clanipedbetween two copper heads hhJQNear the periphery-of the drumthus formedit isbored in the line of its axisat seventeen equidistant points, andthe metal is also slitted, as at i, ,through'theouter side r of eachhole, thus dividing the face of the ar mature into seventeen divisionsor teethwith intervening air -spaces. Into these holes softcopper plugskaretightly inserted; Concentrio with these outer holes a correspondingnumber of smaller holes" are bored, each slightly opening into theadjacent large hole.

Into thesesmall holes soft-copper plugs or pins are fitted, each pairotsmall and large plugs being in contact with .each other and serving insubstance as one conductor of such a form as will possess desirablesectional area without unduly reducing the'bulk of iron be-, tween eachpair of the thus-connected con doctors, this iron being required foraffordin'g magnetic circuits. The copper heads h h and the several plugsor pins is k are then united by solder at all the joints, thusproducin'g an armature which is a practically solid integral structureand one which cana not become injured or impaired by service,

and hence need never be dismantled Referring to Fig. 2, it will beseenthat the" magnetic circuit from no one field-pole through theadjacent'iron in the armature- :core to any other field-pole can ever beprecisely the'same (in magnetic conductivity) as any other magneticcircuit between any 'other'two field-poles, because of the unsymmetricalrelations betweensaid .field 50183 'and'the divisionslof the iron corenear its pe- -riphery.' Now,vreferring-to the novelty believed to beinvolved in the ar'maturesdevised, it is to be understood thatclosed-circore embody a' 'portion of the inventionre- 'ouitarm'aturesembodying thetransverse cop- -per plugs and the copper headson an'iron L gardless of the relation which the number of closedcircuits may bear to 'the numberoffield-poles or pole-faces. Armaturesof this type, although composite, are practically solid structures, theparts .being generally solidly united at all points bymeans of solderor, welding, so that the core and the closed-01rcuit conductors arepractically'integral, and it istherefore considered that anarmatureaffording equal magnetic resistance in all directions embodie's avaluable portion of the invention fo'rj instance, as shown in Figs.

3and 4. This armature B is co'mposedwholly 3 r of iron,an'd it maybe'made up of soft-iron v disks or of solid'iron either wrought or cast;

At its periphery it is radially slitted at re'gu lar intervalsgras at 9but leaving the ends 9 of the drum int'act,-the slots 9 being concave,

as shown. In this instance there are seventeen'of these slots and acorresponding nuni beret faces g at theperiphery, the closedcircuits-being afforded in.-each instance from each of the faces 9 tothe one or two diametrically opposite (if-- used with a bipolar field)or from each face g to s'uchothe'r face'or faces as may in, each case beappropriate to'the polar arrangement of the field. It will be Seen thatthis armature-core it placed in the machine, Figs. '1 and 2, wouldprevent any one magnetic circuit through the core from any twofield-poles from being precisely thesame in inagneticconductivity asthat of any other two field-poles;

In Figs, 5 and 6 is shown an armature B which has a laterally-mortisedcore g, the mortises being open at'the periphery and filled ICO withcopper barsk which project at their er niibs and occupy mortises incopper heads h solder or welded together, and the copper heads, as inthe armature first described,

serve as diametrical conductors.

In Figs. 7 and 8 is shown one of the arma' tures in one of its bestforms so far as relates to itsstructure. This armature B has closedcircuits which are'afiorded by copper heads k k and three annular setsor rows of copper plugs, of which there are thirty-four in each row, theouter-plugs k in the slotted holes being larger than those in the middlerow Z0 and these latter larger than those in the inner row kThisgraduation in the sizes of the plugs in the three sets or rows 7This armature is solid and practically integral, the several jointsbeing flooded with provides for sufficient intervening iron to af-w fordample magnetic circuits. In this armature the plugs or conductors of theseveral sets are also so arranged that the conductors in some of thesets occupy different radial lines from those occupied by the conductorsof another set. V The conductors of the different sets may be arrangedin variousways, and any desired nu mberof sets may be employed; but inany case there will be adjacent sets in which the conductors are solocated with respect to each other that a radialline through the centerof a conductor ofione set will 'not pass through the center ofaconductor of the other set.

In Fig. 9 the motor A has an armature B, likethat shown in Fig. 1, and afield having cheeks or pole-pieces surrounded by fieldcoils a andrecessed, asat t, for enabling it to receive a closed-circuitedstarting-coil in the form of a solid ring or conductor i which embracesone-half of the cheek, as clearlyindicated in Figs. 9 to 11. The edgesof each cheek are slightly rounded. The electrical arrangement of thecoils a with their lineswitch or cut-off and the relative positions ofthe closed-circuit starting-rings t are clearly indicated in Figs. 11and 12. The rounded edges of the pole-pieces or cheeks enable thearmature to start more readily and to more bination with a set offield-poles, a closed-circuit armature having an iron core which,adjacent to its periphery, is divided into sections on substantiallyradial lines, said sec tions being always located unsymmetrically withreference to the field-poles, substantially as described, whereby at notime will any two pairs of cooperating poles have magnetic circuitswhich are precisely alike in magnetic conductivity through adjacentportions of the core.

2. In an alternatingcurrent motor, the combination of a set offield-poles, and a'set of longitudinal plugs, in an armature, serving asclosed-circuit conductors, said poles and plug-conductors being locatedunsymmetrically with reference to each other, and at no time, whether atrest or in motion, having any two adjacent plugs (on different radiallines) occupying the same position with relation to the adjacent pole orpoles, as that occupied by any other two similar adjacent plugs, withrelation to their adjacent pole or poles, substantially as described.

3. An alternating-cu rrent-motor armature, substantially as hereinbeforedescribed, provided with a set of closed circuits, aitorded bylongitudinal plugs and diametrical copper heads which are solidlyincorporated with an iron drum or core, said plugs being arranged eachother that a radial line through the center of a conductor of one setdoes not pass through the center of a conductor of the other set. i

6. An armature composed of a core of magnetic material, circular endconnections of conducting material, longitudinal plugs or conductorsembedded in said core, and in said end connections, the said plugs andend connections being united by solder.

7. An armature composed of a core of magnetic material, end connectionsof conduct ing material, longitudinal plugs or conduc tors embedded insaid core, and in said end connections, the said plugs and end connections being so united as to be practically integral.

8. An armature composed of a core of magnetic material, circular endconnections of conducting material and longitudinal plugs embedded inthe magnetic material and with their ends embedded in said endconnections.

9. An alternating-current motor having a toothed inducing member and atoothed induced member the number of teeth in the two members being sorelated to each other as to have no common divisor greater than one.

10. An alternating-current motor having a toothed inducing member and atoothed induced member the number of teeth of the two members beingsochosen with respect to each other that a tooth on one member bears tothe nearest adjacent tooth on the other member a relation different fromthat between another tooth on the first member and the nearest adj acenttooth on the other member.

11. In an alternating-current motor, the combination with the inducingmember, of a squirrel-cage armature having its conductors so locatedabout its periphery, as to present to the polar projections of theinducing member different relations respectively between theconductor,or conductors,adjacent to onepolar projection and theconductor, or conductors, adjacent to the next adjacent polarprojection.

12. In an alternating-current motor, the combination of inducing andinduced members, one of which is provided with polar proj ections andthe other with conductors which form the seat of induced currents, theconductors being so arranged as to produce, with every variation in therelative position of the inducing and induced members,a relation between one polar projection and the conductor or conductors adjacentthereto which is different from the relation existing between the nextadjacent polar projection and the conductor or conductors adjacent tosaid lastmentioned polar projection.

13. A dynamo-electric machine having its two relatively-rotating membersprovided with teeth, the numbers of teeth on the two members beingrelated to each other in such a manner as to produce substantiallyuniform magnetic resistance of the magnetic circuit between the twomembers in all the relative positions assumed by the said members duringoperation of the machine;

14. In a dynamo-electric machine,the combination of an'inducing memberprovided with exciting-coils and an induced member provided withpermanently-short-circuited conductors prime in number to the number ofexciting-coils.

15. In an alternating-current induction-mor tor, the combination of afield member havvisible by the number of pole-faces of the field or hasno large commondivisor therewith.

In witness whereof we have hereunto set our hands this 9th day ofNovember, 1900.

CARL EICKEMEYER, MARY T; EIGKEMEYER, 'RUDOLF EICKEMEYER, JR.,

Easecutors of the late RudolfEickemeg er, de- 1 ceased.

Witnesses:

ARTHUR A. BUCK, JAMES D. IvERs.

